There are several tourniquets on the market that can be used in cases of severe limb hemorrhage. Such tourniquets typically involve cinching, to remove slack from the tourniquet, followed by tightening, to apply pressure to the limb. Many tourniquets have been made as devices that require two hands to effectively apply them, making them inappropriate for self-application. A few tourniquets that are applicable with just one hand, of the type described in U.S. Pat. Nos. 7,892,253 and 7,776,064, require dexterity to cinch using cumbersome one-way buckle and/or clasp features, which cost valuable time when self-applying the device in a high stress scenario. This proves to be a hindrance in the cinching process, making the application of the tourniquet difficult and slow.
U.S. Pat. No. 6,960,223 describes a tourniquet that may be applied with one hand with gross motor skills, or minimal dexterity. This tourniquet consists of two concentric loops formed such that pulling on the outer cinches the inner loop. However, pulling on the outer loop also creates friction between the loops, preventing the mechanism from effectively working. This locking friction effect makes it more troublesome for the user to apply the device, if at all. This complication again leads to longer application times, especially in high stress scenarios. In the case of a tourniquet, a longer application time can be critical to the survival chances of the user.
Many tourniquets have been made as devices that can be applied only on limbs with an accessible open end. These tourniquets are in the form of closed loops and can only be slid on from an open end, making them impossible to apply on entrapped or severely mangled limbs. A few tourniquets that are applicable on such limbs, of the type described in U.S. Pat. No. 8,343,182, are in the form of open loops that may be closed during application. However, accidental opening of the loop after application is a concern with these tourniquets. Additionally, significant dexterity is required to open and close the overall device loop.
U.S. Pat. No. 8,652,164 describes a ratcheting tourniquet which can be tightened using gross motor skills or minimal dexterity. However, the cinch method is cumbersome: the loosely-bound device has to be anchored using either the teeth or another limb, if available, to fully affect the cinch prior to the ratchet tightening. This adds an extra step, and slows down the overall application of the device.